Jay;
I dislike what T C-T has down intensely, but go careful with the facts. You wouldn't see a customs clearance at Farnborough, because if one is required out bound then it is dealt with in the main terminal, if required in-bound it is often dealt with on board if it is a private jet, otherwise the terminal for something smaller.
I know this because I fly out of Farnborough several times a month. My knowledge of EGLF customs is based on fact. Edited video can be extremely misleading.
SND